A bottle type and a wide-open type resealable metal can container, in which a container mouth and a can trunk are integrally shaped from a metal sheet and a bottom lid is seamed to an bottom end, and a bottle type and a wide-open type resealable metal can container, in which a can trunk and a bottom portion are integrally formed from a metal sheet and a container mouth is formed by drawing an opening end of the can trunk, are widely known in the prior art.
As disclosed in Japanese Patent Laid-Opens No. 2003-321039 and No. 2004-26306, the above-mentioned bottle type and a wide-open type resealable can container comprises an outwardly curled portion on an open end of the container mouth. In addition, a resin sealing liner to be contacted with the curled portion is affixed to an inner face of a closure thereof.
It has been considered to use a welded can body formed by rolling a metal sheet into cylinder and welding overlapped longitudinal edges of the metal sheet for manufacturing a resealable can container to be closed by a closure, instead of the above-mentioned seamless can in which a container mouth and a trunk portion are formed integrally from a metal sheet. In order to use the welded can body for manufacturing a resealable can container, it has been considered to form a container mouth to which a closure is applied on one of open ends of the welded can body.
However, the welded can body is prepared by overlapping longitudinal edges of the metal sheet and welding the overlapped edges as explained above. As a result, a level difference is inevitably formed at the welded portion even if the manufactured can is a small can made of a thin metal sheet. Here, it is quite difficult to completely eliminate the level difference resulting from welding the overlapped metal sheet. This means that such level difference appears inevitably on a surface of a curled portion formed on an open end of the container mouth of the welded can body.
When a closure is applied to the container mouth, a clearance has to be created between the surface of the curled portion and a resin sealing liner by the level difference of the welded portion on the curled portion being contacted with the liner. As a result, sealing ability may be degraded.